This invention relates to a dumbbell, particularly to one having a bar, a weight respectively fixed with two ends of the bar and containing iron sand wrapped in an elastic cloth bag and changeable to a different weight according to a user's need. In addition, the weight is flexible in its shape, so when the dumbbell falls down on the ground by accident, it cannot produce large sound, or hurt the feet of the user owing to its flexibility, and thus is very safe to use.
A known conventional dumbbell shown in FIG. 1 includes a bar 10, a contact edge 11 formed at two ends of the bar, a support end 12 respectively formed to extend outward from the stop edge 11, a weight 13 of different weights fitted on the support end 12. The support end 12 has an inner threaded hole 120 and a stop means 14 screwed with the outer end of the support end 12. The stop means 14 has a threaded rod 140 extending outward to screw with the inner threaded hole 120 of the support end 12, with the stop means and the stop edge 11 limiting the weight 13 on the support end 12 in a stabilized condition. When the weight 13 is to be changed to another one, only loosen the stop means 14 and take off the old weight the support end 12, and then put a new weight 13 on the support end 12 and screw tightly the stop means 14.
However, the weights of the conventional dumbbell are generally a hard solid one, to a user may often let it fall down carelessly, producing an extremely large sound with the weights broken. So a user has to use it very carefully, lest he should let it fall down to hurt a person around. Moreover, if the stop means 14 should loosen and fall down for an unknown reason, an accident may happen.